Steam-engine.



s. ROSENZWHG. STEAM-ENGINE.

APPLICATION FIL ED AUGJI, 1916.

Patented July 3, 1917.

4 SHEETS-SHEET I.

S. ROSENZWHG.

I STEAM ENGINE.

APPLICATION FILED AUGJI, 191s.

Patemfi. July 3, 191?.

4 SHEETS-SHEET 2.

s. ROSENZWEIG. STEAM ENGINE.

APPLICAHON FILED AUG-11,1916- Patented July b, 1917.

4 SHEETSSHEET 3.

S. ROSENZWHG.

STEAM ENGINE.

lygggggs. I APPLICATION mm Ausm, 3916. Patnted July 3,1917" '4 SHEETSSHEET 4" return stroke.

* uni STEAM-ENGINE.

naaaoea,

- Specification of Letters Patent.

Patented July a, ram;

Application filed hugust 11, 1916. Serial No. 114,438.

To all whom it may concern:

Be it known that I, SIEGFRIED ROSENZWEIG, a citizen of the United States, residing in New York city, in the county and State of New York, have invented a new and useful Improvement in Steam-Engines, of which the following is a specification.

My invention relates to unifiow engines having a central main exhaust port in the steam cylinder wall uncovered by the piston toward the end of the expansion stroke, and auxiliary exhaust ports, and mechanically operated controlling valves therefor, through which steam escapes after the main exhaust has been closed by the piston on its return stroke. The main exhaust is uncovered by the piston after expansion has taken place, the exhaust usually commencing about before dead center. As this main exhaust is closed by the piston on its return stroke, compression necessarily commences approximately 10% after dead center, and, in the absence of the auxiliary exhaust, would last for about 90% of the While high compression is advisable and economical in uniflow engines, yet it has 'unifiow engines as the exhaust pressure increases in order to prevent excessive compression pressures. Such devices are necessary with the comparatively low boiler pressures at present in prevailing use, but it is obvious that with higher boiler pressures such as are now being introduced, no mechanical means are needed to overcome this excessive compression pressure, inasmuch as,

with increased admission pressure, the compression curve will not rise above the admission pressure. i

Tint leaving the question of excessive compression pressures out of consideration, it is the fact that, to produce the most favorable results, compressions should vary with cut-off of the engine in order to get most economical operation and secure best results.

To this end I combine with the steam admission and main exhaust means of a uniflow engine, auxiliary exhaust valves and operating gear for each auxiliary exhaust valve, including an eccentric adjustable to vary the extent of its eccentricity, and mechanical hand-operated means arranged and adapted to be operated, whether the engine be in motion or at rest, to thus adjust said eccentric and hold it in its adjusted position. It is in this combination of instrumentalities, which I believe to be new with me, that my invention is comprised.

To enable those skilled in the art to understand and use my improvement, I will now proceed to describe the manner in which the same is or may be carried into practical effect by reference to the accompanying drawings, in which Figure 1 is a side elevation of so much of a uniflow puppet valve engine embodying my invention as needed for the purpose of explanation.

Fig. 2 is a plan of the same.

Fig. 3 is a longitudinal axial section on enlarged scaleof the steam cylinder showing. the location of the steam admission and exhaust passages, and of the steam admission valves and auxiliary exhaust valves, the

its stuffing box removed, showing oneof the steam admission valves and one of the auxiliary exhaust valves in longitudinal axial section, together with the valve gear for each valve partly in elevation and partly in sec-' tion.

Fig. 5 is a longitudinal axial section of the mechanical hand-operated device for adjusting the driving eccentric of the auxiliary exhaust valve gear.

Fig. 6 is an elevation of said eccentric, the block on which it can slide, and the eccen-i tric strap and connecting rod, with the hollow governor shaft (on which said block is secured) and the central stem of the eccentric-adjusting device within said shaft, in cross section.

Figs. 5 and 6 represent on enlarged scale the structural details of the said mechanical hand operated device and its relations to and connections with the hollow governor shaft, the slide block thereon and auxiliary exhaust valve gear eccentric mounted and adjustable on said block, and are intended for that purpose only-the eccentric straps being shown as shifted out of the position they occupy in Fig. 4, so as not to obstruct the View of the structural details of the said hand operated adjusting device. 1

Referring more particularly to Figs. 1, 2 and 4, 1 are the the bonnets or housings for the tappets on the rock shaft 2, for operating the tWo steam inlet valves, located at opposite ends of the cylinder; 3 is the eccentric strap and its connecting rod, through which motion is imparted from the eccentric on the governor shaft at to the rock shaft 2; 5 is the housingjafljf the governor, which latter is mounted on the governor shaft at and connected in the usual way to the said eccentric; 6 are the bonnets or housings for the cams or tappets 011 the rock shaft 7 for operating the two auxiliary exhaust valves, which latter, like the steam inlet valves, are located at opposite ends of the steam cylinder; 8 is the eccentric strap and connecting rod through which motion is imparted from an eccentric on the governor shaft to the rock shaft 7said eccentric being separate from and independent of the steam inlet valve eccentric.

Referring now to Figs. 3 and 4-, 9, 9, are the steam inlet ports; 1O, 10, the puppet valves controlling the same; 11, 11, the auxiliary exhaust ports; 12, 12, the puppet valves controlling the same; 13, the main exhaust ports and passagesrlocated centrally between the ends of the cylinder; 14, ducts leading from the auxiliary exhaust ports and passages to the main exhaust passages 18; 15, the operating eccentric of the valve gear for actuating the steam inlet valves; 16, the operating eccentric of the valve gear for actuating the auxiliary exhaust valves; and 17, the reciprocating steam piston which controls the central exhaust 13. S, Fig. 3, is the stuffing box in the head of the steam cylinder through which the piston rod passes, containing the piston rod packing and associated with the usual gland and system of lubricating piping and passages as shown.

l Vhile the parts above named are necessary to an understanding of my invention, yet, as thus far described, the structure is well known and requires no detailed description. v

I come now to a description of those parts of the structure-in which my invention is embodied.

pends upon the position The auxiliary-exhaust eccentriolti, which is entire'lyindependent of the steam admission eccentric, is not keyed to, or otherwise secured in fixed position on, the governor shaft, but it is mounted on, and slidable lengthwise of, a guide bolck a keyed on said governor shaft. For this purpose there is formed in the body of the eccentric, as indicated more particularly in Figs. 4 and 6, an oblong openiiig b of sufliciently greater length than the block a to permit it the requisite range of movement on the block for the purpose of varying the degree of eccentricity of said eccentric and consequently the throw of the auxiliary-exhaustvalve actuating rock shaft 7, the longer parallel faces of said opening I) fitting upon, and in slidable engagement with, the opposite parallel longer edges of said block a, whereon the eccentric is held by, and between, suitable parallel guide flanges c, c, as indicated in. Fig. 5. The flanges are omitted from Fig. 6 to aivoid obscuring the parts.

The position in which the guide block a is set upon the governor shaft will determine the particular point in the stroke of the steam piston at which the auxiliary exhaust opens. The shifting of the eccentric on its guide block will not affect this feature. The effect of the shifting of the eccentric is merely to vary the degree of its eccentricity, and consequent throw; but however much this may be varied, the auxiliary exhaust valve will, for all practical purposes, always open at the same point in the return stroke of the piston. This is of material advantage in engines of the type here shown, because the main exhaust 13 is closed by the time the piston has completed 10% of its return stroke from dead center, and it becomes necessary to provide a means by which the auxiliary exhaust on that side of the piston will be open by the time the main exhaust is closed. For this purpose the auxiliary exhaust valve should preferably open approximately at dead center. This result can be attained with certainty by the use of the means described, for the reason that if the slideblock be once set so that the eccentric drive and valve gear will open the auxiliary valve at approximately dead center, it will al ways open at that point (if it opens at all) no matter to what extent the eccentric may be shifted upon its block a. The set of the guide block determines the point in the return stroke at which the auxiliary exhaust valve opens, and the point at which the subsequent closing of said valve takes place dethe eccentric occupies on its guide block a and the consequent degree of eccentricity at the time.

- The means employed by me for thus adjusting the eccentric upon. its guide block and retaining it in its adjusted position, consists of a manually operated mechanical device, mounted upon the cylinder or some other convenient stationary part of the engine, and combined with connecting means whereby it may be actuated by hand to shift or adjust the eccentric on its guide block at will while the engine is in motion. This not only permits the eccentric to be shifted, while the engine is running, as may be re quired by prevailing steam and exhaust conditions, to obtain any given degree of compressiona feature of prime importance; but is also valuable when starting the engine, inasmuch as it makes it possible to put the engine in operation with a minimum compression, thus facilitating its starting, and subsequently, as the engine gets under head- Way, to increase the compression until it reaches the desired degree.

The working parts of the device are inclosed in a bracket casing 03 secured to some convenient stationary part-in this instance the engine cylinder-4n suitable proximity to the auxiliary exhaust eccentric 16, as seen in Figs. 1 and 2. This casing is shown in longitudinal vertical central section in Fig. 5; and, as there indicated, it has an axial cylindrical bore which receives and forms a bearing for the extreme end of the governor shaft l which extends through and beyond the auxiliary exhaust eccentric 1G. The governor shaft is tubular, and receives with-, in it the operating stem 6 of the shifting device, having its end nearest to auxiliary exhaust eccentric 16 enlarged to form a cylindrical head f of such size and proportions as to fit the bore of the tubulargovernor shaft 4: and to be slidable therein, the shaft 4 furnishing an accurate bearing and guide for the thus-movable stem. In the head f are formed two slots or grooves g, g, which extend on the prolongation of one another, lengthwise of, and diametrically through, the head, the two being separated by a diagonal partition or wall 6, which furnishes an inclinedbottom for each groove 9, 9'. With these grooves are associated shifting pins or studs h, it, one for each groove. The conjoined length of these pins, plus the thickness of the partition which intervenes between their abutting ends, will equal the length of the oblong opening I; in the auxiliary exhaust eccentric 16, so that when said pins are placed on opposite sides of the partition, one on the prolongation of the other, their outer ends will bear against the opposite ends of the opening Z) and their inner ends against the inclined floor provided by the diagonal partition 25. The pins, to occupy this position, must, of course, pros, trude through the walls of the tubular governor shaft 4 and block a; and to this end, two diametrically opposite holes '6', i, are formed in the wall of the tubular shaft 4, and corresponding registering holes 71:, 7e, are formed in the block a. These holes through which the pins pass, and the side walls of the grooves g, g, furnish guides which assure and steady the pins in any position they may occupy, as well as in their in-and-out movements from one position to another. If the stem (2 be moved lengthwise in the shaft a, one of the two pins will be protruded, according to the direction of movement of the stem, and the ther one will be free to recede to a. corresponding extent; and, as the outer heads of these pins hear at all times against the opposite ends of the opening I) in the eccentric 16, the latter, by the pushing action of one or the other of the pins, willbe'caused to slide on the block t increase or decrease the degree of its eccentricity, according to the direction of the pushing movement.

The operating stem 6 revolves with the governor shaft 4:, and a connection must therefore be provided between. the stem and the hand device for operating the which will permit the hand device to more the stem lengthwise, without partaking of 1ts rotary movement; and to this end a cap Z is aflixed to the outer end of thecasing d,

which is bored out cylindricaily for a portion of its length as at an to a cylindrical coupling box a, which fits and is free to slide and rotate therein. he. coupling box contains the abutting cylindrical heads 6 and 0 of the stem 6 and screw spindle 0 respectively, which fit the cylindrical interior of the coupling box; The screw spindle 0 passes through and engages an internally screw threaded sleeve 79 extending through, and supported in, a bearing in the outer end of the cap Z, in which it is capable of rotary movement only as shown. Gn the projecting outer end of the sleeve 30 is a hand wheel a" for operating the same. On the screw spindle 0 is a radially projecting pin (1 which enters a guide slot 3 formed in and lengthwise of the cap. Thus, when the internally screw threaded sleeve 19 is rotated by the hand. wheel 7, the screw spindle will be caused to'move lengthwise only without rotation, and thus, through the coupling box a, imparting corresponding movement to the operating stem 0, the direction of which movement will be determined by the directionin which the hand wheel r is rotated. In this way, while the engine is in motion, the auxiliary exhaust eccentric 16 can at any time be readily and surely adjusted by hand to vary the di rec of eccentricity as desired.

Having described my improvement in uniflow engines, and the best way now known to me of carrying the same into practical effect, I state in conclusion that it not limit myself narrowly to the structural de tails hereinbefore shown and describec in illustration of the invention herein claimed, since manifestly the same can be varied in a number of particulars Without departure from the spirit of the invention: But what I claim herein as new and desire to secure by Letters Patent, is as follows:

In a unifiow engine, the combination with the steam admission, cut-0E, and main exhaust instrumentalities, of auxiliary exhaust ports and controlling valves therefor; operating gear for said auxiliary exhaust valves, a drive shaft, anda driving eccentric for said auxiliary exhaust valve gear, independent of the steam admission and cut-oif instrumentalities, mounted on said shaft and adjustable thereon to vary its degree of eccentricity only relatively to said shaft,

whereby while the period of opening of the exhaust valve actuated by said valve gear will vary with the degree of eccentricity of the eccentric the opening of said valve will always take place at substantially the same point in the return stroke of the piston; and mechanical hand-operated means mounted on a stationary part of the engine, and arranged and adapted to thus adjust said eccentric whether the engine be in motion or at rest, and to hold it in its adjusted position, substantially as and for the purpose hereinbei'ore set forth.

In testimony whereof I aliix my signature.

SIEG FRIED RUSENZVVEIG.

auxiliary 

